Funding for this research was provided by:
Natural Science Foundation of Shandong Province (ZR2016HM31)
Received: 15 May 2020
Accepted: 10 August 2020
First Online: 22 August 2020
Ethics approval and consent to participate
: Ethics committee of affiliated hospital of Qingdao university approved a waiver of consent for this retrospective study.
: Written informed consent was obtained from the patient for publication of this research and any accompanying images.
: The authors declare that they have no competing interests.